So I have two tubescreamers - A TS-5 Soundtank and a Maxon OD-9. They are both broken. I also have a Boss SD-1 but it is no replacement for teh screamrar of toobs.

The Maxon's drive knob doesn't function properly, probably due to a tumble in my backpack. Now I always transport pedals in boxes.

The TS-5's footswitch doesn't work anymore and it has a constantly crackle-hissing that makes it not very usable even if I could engage it.

Now I don't know how the hell I'm going to fix the TS-5... the Maxon I'd simply have to order a new pot.

Good thing the more expensive one is the easy fix, right? Well actually, no, because the TS-5 is mysteriously the best tubescreamer I have ever played. It seems darker or fatter or gooier and generally does something very good to tube amps. The OD9 seems boxy sounding in comparison.

So I've opened them up while reading up on the circuits and I found something interesting. There's a pair of resistors in most tubescreamers that you'd swap for other values to get the thing to TS808 specs. According to the internet this applies to the TS-5 and the rest of the common ones:



I've discovered though that the OD9, yes, it has a 470 and 100k ohms resistors. But interestingly, the TS-5 of mysterious provenance has the 808 rated resistors. This is my observation; the internet says they should be the TS9 rated ones instead. Could this be why the pedal sounds so much better to me?

According to all the blues rockers' descriptions of the differences between the two pedals that I find when I google... maybe.

It might also be that the opamp chips are different. The TS9 has the tr00 grim original chip and the TS-5 has some other shit. But fuck, how do you unsolder all eight legs of that chip? Fuck that man. Chris, if you can share some learning with me on how that is done I'd love to hear it.

So I guess what I'm going to do is replace the broken pot and then switch them resistors. And we'll just see what happens after that.

You might try the swap of the TS5 output bits, but i would almost think it more likely that the difference in sound is more likely to be due to random component values supposed to be one thing that are measuring something else. It is reasonably difficult to make two pedals that sound exactly the same when compared directly A to B. I am not looking at any TS schems at the moment, but it is totally conceivable that capacitor differences in the output stage could affect the sound of the thing. It is a buffer though, so i wouldn't necessarily expect it to be massively different. Maybe if it drastically alters the output impedance...

As for removing IC chips. 1. Swapping them doesn't make THAT much of a difference, in my experience, and when they do, it tends to my ears to be more about how they clip, than any eq characteristics. 2. The only way to do it without wrecking shit is to use desolder braid or a solder sucker. You CAN unsolder them without those things if you get a little sneaky, but it is extremely difficult to do so without completely fucking up the circuit board and lifting traces, that sort of thing. Use the sucker or the braid and it actually becomes kind of an easy task.

Aslo, it may in fact be that the pot is not at all broken, but that perhaps the connections to it might be. before you run out and get a new pot, at least try reflowing the solder joints on the three lugs on the bad one. You might very well find that this cures it. Sometimes when shit gets banged around, the solder joints crack a bit. Additionally this can happen easily with pots if the nut on top loosens up a bit allowing the joint to flex more than normal as the pot moves slightly. Doesn't take much movement to screw up a solder joint really.

I don't know enough about this shizzle to guess where the crackle/hissing is coming from on the TS5, but could you re-house it in a box with a working footswitch easily enough?

Might be a slight pain in the cock to do that, simply because the current system of switching, which is probably like a flipflop transistor or switching ic sort of deal, would have to be bypassed/removed.

Though honestly, it is a popular and useful enough pedlol that i would not at all be surprised if there existed out in internetland, some set of detailed instructions detailing the process in such a form as to make the process for doing so very simple. That just seems to me to be the type of thing one could locate tangled in the internets if one sought it oot.

I think I've heard of people putting the Soundtanks into, y'know, proper metal enclosures before? But I could be wrong? I know the TS7 is a popular enough mod platform. Both are Tube-creamers, and both are cheep, so...

I'm going to look into this whole deal with people rehousing the Soundtanks. It seems tedious, what with the board mounted pots. Actually a metal enclosure might kill a lot of the background noise. After all, I don't think I recall it ever not being noisy, though I do believe it is noisier than it was when I first got it. The actual switch is a tiny flimsy thing. The only ICs on the TS5's board is the main opamp. Flip flops sound like they might be it.
Hm... I guess it might be possible to transplant the board mounted parts (9V jack, input output jacks, knobs), get a better switch, and rehouse the whole thing. I`ve emailed small pedal modder guys about it but no one is interested.



Durr... the drive pot doesn't work because, I believe, it is touching the side of the pedal. That should be a quick fix! Too bad it doesn't sound like the TS-5 of mysterious provenance. I am considering seeing if any other resistors or caps are not expected values, because I`m considering attempting to make the OD9 sound like my TS-5. Possibly even using its opamp. I do possess a solder sucker. And I have shit loads of those little IC docks to put for quick transplants.

So here's someone's TS-5. The resistors are big and he has a JRC opamp. I'll also bet he has the expected resistances on his output, unlike mine. Mine has little shit resistors and a different opamp. Arg, am I going to open it up again?




Looks like a Toshiba opamp.

Are both opamps 4558s? If so, i would look elsewhere to start. It is easy to fall into the "opamps make a huge difference" thing, but in reality, there is very little there between very different types, and almost nothing between ones of the same type.

If you wanted to ship it, i could easily do the rehouse for you. But i do suspect that the information is out there for all levels of electronics knowledge/skill. Essentially, you wiether need to trick the thing to thinking it is on all the time(only works with certain switching setups, others will need a second switch to turn it on every time it powers up, in addition to the bypass switch), or you need to remove all of the switching parts and jumper it so that it doesn't bypass at all, then just putting in a normal 3PDT switch for that porpoise.

If you can read a schematic, you can figure it out. If that sort of thing gives your brain guff, like i said, i really suspect that the information is probably out there in the form of a photo essay or instructable, or just some sort of detailed walk-through of the procedure for the soundtanks. They are popular cheapo sleepers, prime candidates for the modification.

The OD9 is JRC4558, the reissue of the type that everyone considers a 'holy grail'

The one in my TS5 is a TA75558p, generally a frowned upon one.

As soon as I've done some domestic bullshit around here I'm going to fix the OD9 and then examine the TS-5 closely.

Well I was wrong, misread the circuit in my TS-5... it DOES have the output buffer resistors as expected, like a TS-9 and not an 808. It's got to be either the opamp or as you are saying, just the tolerances of the cheap little components in here. So if I really want the tone of my TS-5 back I'm just going to have to rebuild all the broken/board mounted bits and rehouse it.

So a few questions... Is there any chance the board mounted pieces (which I would be replacing if I were to rehouse the pedal), that is the knobs and jacks, are playing a role in making it sound the way it does, so replacing them would defeat the purpose?
Also do you think the shitty switch we would replace could be making the pedal sound how it does? Here is a link to the TS-5 schem: http://music-electronics-forum.com/atta ... reamer.pdf

I got the OD9 working, just had to move the pot.

Okay.

1. Knobs will make no difference at all. Ever.

2. Jacks will not make a difference unless the ones in it are covered in oxidation(basically broken) which will make them not pass signal correctly.

3. To replace the pots(which you might/usually need to do to rehouse) you *might* get a different sound, only because the value of potentiometers varies a lot more than commonly available tolerance resistors tend to. This actually is not a big deal, as long as the new pots measure at least the value of the old ones, you will be able to get all of the same sounds. You might find that the sounds you like wind up at different places on the settings though, because of differences in pot taper and/or value. The sounds will still be there, just maybe at a (slightly) different setting.

4. Shitty switch(it isn't really shitty, honestly), should not make any difference at all to the sound of the pedal when it is on. If broken/fuckedup, the transistors could potentially add noise to the effect, but mostly they will not do anything bad until the effect is off/bypassed. The whole true bypass thing has moastly nothing to do what the pedal sounds like when engaged, only how it affects the signal when it is off.

5. Just as a general aside, i have used a lot a lot of chips in ODs, including the JRC4558 and a pile of "nicer" and "shittier" ones, and none of them really make very much difference in the same circuit. Certainly not in any way that i would get too worked up about. There are certain oddball ones that sound shitty in a wonderful way(e.g. the LM741 in the Hotcake and a pile of other pedals, the LM308 in the Rat) but they are very much exceptions to the rule. In some builds i have done i like certain chips, but it is more because of something terrible i have done to them to make them distort. The Tubescreamer doesn't really get too crazy with that end of the circuit party, and i have really not found any difference that is worth going out of my way to make use of. Honestly, i have heard just as much sonic difference between the exact same labeled chips, as i have between the typical types that wind up in ODs.

This guy has the same two pedals in comparison, and he seems to feel similarly to how I do about where they each stand. Except both of his work.



Been reading up on the TS-5 and people have switched the opamps, the output buffer resistors, and it's still always the fatter darker one. Starting to think maybe the switching or something is the actual key to it sounding how it does.

Haha yeah, when I said 'knobs' I meant the pots. Knobs are pieces of plastic.

I am convinced that the opamps don't make much difference also now, as reading up on other TS-5 owners' experiences they changed those and all sorts of other things (output buffer resistors) and it always sounded fatter. So it's something else causing this.

Gonna check the resistance on these hurr pots, maybe they are some other rating that is making the difference.

I would be curious to know what the measured values of C10 and R18(using the labeling from the schematic you poasted) are in the TS5.

That video is very difficult to tell due to the camera compressing on all of the attacks, but the TS5 sounds perhaps a bit bassier and more distorted.

While this could conceivably be due to the opamp, well the distortion anyhow, i suspect that it is much more likely to be due to component value differences.

I don't think it is likely to be due to the jacks or switching.

If those are the resistor and cap responsible for where the pedal cuts off the highs and lows I think we might be thinking the same thing! Just makes sense. I assumed they'd be the same but when I get home we'll just see if this is actually the case...

It probably seems retarded that I've been wondering if it's things like the switching circuit or opamp that make it so special but you've got to understand, the core of the circuit is supposed to be identical in both. Tolerances may play a role though..

Home from work: The cap and resistor you were asking about are 4.7k and .047uF in both the TS5 and OD9.

This article at geofex.com which I've been reading over and over (it's so full of information that this never seemed redundant) has suggested this:



Dunno how I missed that. Now where is the bias supply section so I can poke it with my multimeter.

Tolerance differences are massive. Especially as they pertain to caps, which usually have lousy tolerance specs(vs resistors where it is pretty cheap to get 1% ones) and in addition are not as easy to check, with capacitance measurement ability not generally being found on inexpensive multimeters. I have a pet theory that quite a bit of the TGP style tone bullshit voodoo talk might really come from unmeasured/unnoticed variations in capacitance, rather than in many of the more far-fetched things that are suggested as being important.

The cap and resistor i mentioned are a network that sets the high pass frequency range of a sort, for the op amp. If values are used to provide more bass, more distortion is also generally the effect, simply because less signal is being bled off at that point. A useful thing to have there is actually a control network, such as the one found on the Timmy OD. The "bass" control on that pedal is actually basically just a pot in a modified network with some carefully chosen values there.

Additionally, i would be curious to see what the TS5 has in it for clipping diodes. There are certainly big differences to be had there. As in opamps though, less tonal differences, and more distortion/clipping ones.

The bias supply will be off the red lead of the 9v connector. It will be a resistor going to ground, a resistor going to vRef/4.5v (usually/often the same value resistor for bofe), and generally a large electrolytic cap(usually/often the largest one in the pedlol). Occasionally there will also be a single diode to ground there which is the reverse polarity protection.